Stable, concentrated herbicidal compositions

ABSTRACT

A liquid herbicidal composition is provided, comprising:
         a. 20 to 35 percent by weight, based on the total weight of the composition, of a water-soluble herbicidal ingredient;   b. a C 12 -C 16  alkyl ether sulfate;   c. an organic solvent; and   d. an alkyl polyglucoside       

     The composition is stable; i.e., it occurs in a substantially continuous, single phase at temperatures as low as −20° C. It also has a viscosity of no more than 2000 cps at temperatures as low as 0° C.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/117,826, filed Aug. 30, 2018, which is a continuation of U.S.application Ser. No. 15/593,355, filed May 12, 2017, now U.S. Pat. No.10,091,990, which is a continuation of U.S. application Ser. No.14/731,848 filed Jun. 5, 2015, now U.S. Pat. No. 9,675,063, which is acontinuation of U.S. application Ser. No. 14/269,813, filed May 5, 2014,now U.S. Pat. No. 9,078,432, which is a continuation of abandoned U.S.application Ser. No. 13/691,411, filed Nov. 30, 2012, which is acontinuation of U.S. application Ser. No. 12/910,243, filed Oct. 22,2010, now U.S. Pat. No. 8,445,406, which is a divisional application ofU.S. application Ser. No. 11/347,773, filed Feb. 3, 2006, now U.S. Pat.No. 7,842,647, the entire contents of which are hereby incorporated byreference in its entirety.

FIELD OF THE INVENTION

The present invention is directed to biologically active crop protectionformulations, in particular, herbicidal compositions.

BACKGROUND OF THE INVENTION

Aqueous herbicidal formulations of glufosinate-ammonium have beenavailable for decades as crop protectants. Popular formulations includesurfactants, which increase the biological activity of the herbicide.High concentration formulations are being sought as well for thenumerous advantages they offer; for example, less packaging is neededthan with low-concentration formulations, corresponding to reductions inthe cost and inconveniences of production, transit, and storage.Preparation of spray liquors is also simplified by the smallerquantities of crop protectant that need to be handled. However, certaindrawbacks have been observed in higher concentration formulations. Forexample, the biological activity of the active ingredient is dependenton the proportion of active ingredient to surfactant, but if the amountof surfactant is too high, the viscosity of the composition may becometoo high for easy handling or spraying. Product instability such asphase separation has also been a drawback of highly concentratedformulations. Phase separation is undesirable because the concentrationof various essential ingredients is no longer uniform throughout thecomposition.

It would be desirable to provide a high-concentration herbicidalcomposition that overcomes the drawbacks of the prior art bydemonstrating enhanced biological activity in a stable formulationwithout compromising viscosity requirements.

SUMMARY OF THE INVENTION

-   -   A liquid herbicidal composition is provided, comprising:        -   a. 20 to 35 percent by weight, based on the total weight of            the composition, of a water-soluble herbicidal ingredient;        -   b. a C₁₂-C₁₆ alkyl ether sulfate;        -   c. an organic solvent; and        -   d. an alkyl polyglucoside.    -   The composition is stable, occurring in a substantially        continuous, single phase at temperatures as low as −20° C. It        also has a viscosity of no more than 2000 cps at temperatures as        low as 0° C.

DETAILED DESCRIPTION OF THE INVENTION

-   -   Other than in the operating examples, or where otherwise        indicated, all numbers expressing quantities of ingredients,        reaction conditions and so forth used in the specification and        claims are to be understood as being modified in all instances        by the term “about.” Accordingly, unless indicated to the        contrary, the numerical parameters set forth in the following        specification and attached claims are approximations that may        vary depending upon the desired properties sought to be obtained        by the present invention. At the very least, and not as an        attempt to limit the application of the doctrine of equivalents        to the scope of the claims, each numerical parameter should at        least be construed in light of the number of reported        significant digits and by applying ordinary rounding techniques.    -   Notwithstanding that the numerical ranges and parameters setting        forth the broad scope of the invention are approximations, the        numerical values set forth in the specific examples are reported        as precisely as possible. Any numerical values, however,        inherently contain certain errors necessarily resulting from the        standard deviation found in their respective testing        measurements.    -   Also, it should be understood that any numerical range recited        herein is intended to include all sub-ranges subsumed therein.        For example, a range of 1″ to 10″ is intended to include all        sub-ranges between and including the recited minimum value of 1        and the recited maximum value of 10, that is, having a minimum        value equal to or greater than 1 and a maximum value of equal to        or less than 10.    -   As used herein, unless otherwise expressly specified, all        numbers such as those expressing values, ranges, amounts or        percentages may be read as if prefaced by the word “about”, even        if the term does not expressly appear. Any numerical range        recited herein is intended to include all sub-ranges subsumed        therein. Plural encompasses singular and vice versa; e.g., the        singular forms “a,” “an,” and “the” include plural referents        unless expressly and unequivocally limited to one referent.        Also, as used herein, the term “polymer” is meant to refer to        prepolymers, oligomers and both homopolymers and copolymers; the        prefix “poly” refers to two or more.    -   With respect to the present invention, the term “stable” as used        herein is intended to refer to physically stable compositions;        i.e., liquid compositions that exist in a substantially        continuous, single phase.    -   In the context of the present invention the term “organic        solvents” refers to, for example, nonpolar solvents, polar        protic solvents, aprotic polar solvents and mixtures thereof.    -   The liquid herbicidal composition of the present invention        comprises a water-soluble herbicidal ingredient (a).        Non-limiting, suitable examples include glufosinate and salts        thereof such as glufosinate-ammonium, glyphosate and salts        thereof, paraquat, diquat, and the like. Mixtures may also be        used.    -   Typically the water-soluble herbicidal ingredient may comprise a        compound of the formula (I) and/or salts thereof:

wherein Z₁ is a radical of the formula −OM, —NHCH(CH₃)CONHCH(CH₃)CO₂M,or —NHCH(CH₃)CONHCH[CH₂CH(CH₃)_(2])CO₂M, where M is H or a salt-formingcation.

-   -   The water-soluble herbicidal ingredient may alternatively or        additionally comprise a compound of the formula (II) and/or        salts thereof:

wherein Z₂ is a radical of the formula CN or CO₂R₁, in which R₁ is asalt-forming cation or is H, alkyl, alkenyl, alkoxyalkyl or C₆-C₁₀ aryl,which is unsubstituted or substituted, and is often unsubstituted orsubstituted by one or more radicals such as alkyl, alkoxy, halogen, CF₃,NO₂ and CN; and wherein R₂ and R₃ are each independently H, alkyl orC₆-C₁₀ aryl, which is unsubstituted or substituted and is oftenunsubstituted or substituted by one or more radicals such as alkyl,alkoxy, halogen, CF₃, NO₂ and CN, or biphenylyl or a salt-formingcation. Typically, the carbon-containing radicals defined as R₂ or R₃have up to 10 carbon atoms, usually up to 6 carbon atoms.

-   -   Note that the compounds of formula (I) contain an asymmetric        carbon atom. The L enantiomer has been observed to be the        biologically active isomer. The formula (I) therefore is        intended to encompass all stereoisomers and mixtures thereof,        particularly the racemate, and the biologically active        enantiomer in each case. Examples of active ingredients of the        formula (I) include glufosinate and/or its ammonium salt such as        in a racemic mixture; i.e.,        2-amino-4[hydroxy(methyl)phosphinoyl]butanoic acid and its        ammonium salt, the L enantiomer of glufosinate and its ammonium        salt or other salts such as potassium, sodium, diethylamine,        triethylamine, bilanafos/bialaphos; e.g.,        L-2-amino-4-[hydroxy(methyl)phosphinoyl]butanoyl-L-alaninyl-L-alanine        and its sodium salt.    -   The water-soluble herbicidal ingredient may be present in the        composition of the present invention in an amount of 20 to 35        percent by weight, often 20 to 30 percent by weight, and more        often 22 to 28 percent by weight, based on the total weight of        the composition. Note that because the water-soluble herbicidal        ingredient is typically provided in a 50 percent by weight        aqueous solution, an equal amount of water is usually provided        with the water-soluble herbicidal ingredient. The numbers in the        ranges above reflect the amount of herbicide only, not the total        solution amount. Additional water may be added as necessary.    -   The composition of the present invention further comprises an        alkyl ether sulfate (b). Alkyl ether sulfates are generally        defined as salts of sulfated adducts of ethylene oxide with        fatty alcohols containing from 8 to 16 carbon atoms. The alkyl        ether sulfates used in the composition of the present invention        are commercially available and may contain a linear aliphatic        group having from 8 to 16 carbon atoms, usually from 12 to 16        carbon atoms. The degree of ethoxylation may be from 1 to 10        moles of ethylene oxide, usually 2 to 4 moles of ethylene oxide.        Examples include sodium lauryl ether sulfate, ammonium lauryl        ether sulfate, and other salts of lauryl ether sulfate. The        alkyl ether sulfate most often used in composition of the        present invention is sodium lauryl ether sulfate (SLES);        typically supplied as an approximate 70% active solution,        derived either from vegetable or petroleum sources.    -   The alkyl ether sulfate may be present in the composition of the        present invention in an amount of 3 to 35 percent by weight,        often 10 to 30 percent by weight, more often 20 to 30 percent by        weight, based on the total weight of the composition.    -   The composition of the present invention further comprises an        organic solvent (c). Suitable solvents may include cyclic        alcohols such as tetrahydrofurfuryl alcohol; aliphatic alcohols,        such as alkanols having 1 to 12 carbon atoms, usually 1 to 6        carbon atoms, such as methanol, ethanol, propanol, isopropanol        and butanol, for example, or polyhydric alcohols such as        ethylene glycol, propylene glycol, dipropylene glycol, and        glycerol; ethers such as diethyl ether, tetrahydrofuran (THF),        and dioxane; alkylene glycol monoalkyl and dialkyl ethers, such        as propylene glycol monomethyl ether, propylene glycol monoethyl        ether, ethylene glycol monomethyl and monoethyl ether, diglyme,        and tetraglyme, for example; amides such as dimethylformamide        (DMF), dimethylacetamide, dimethylcaprylamide, dimethylcapramide        (HALLCOMID®), and N-alkylpyrrolidones; ketones such as acetone,        cyclohexanone, acetophenone, butrylolactone; esters based on        glyceryl and carboxylic acids, such as glyceryl mono-, di- and        triacetate, phthalic esters, ethyl lactate, 2-ethylhexyl        lactate; lactams; carbonic diesters; nitriles such as        acetonitrile, propionitrile, butyronitrile, and benzonitrile;        sulfoxides and sulfones such as dimethyl sulfoxide (DMSO) and        sulfolane; carbonates such as propylene or butylene carbonate.        Combinations of different solvents, additionally containing        alcohols such as methanol, ethanol, n- and isopropanol, and n-,        iso-, tert- and 2-butanol, are also suitable.    -   Solvents that are most often used in the composition of the        present invention include individual solvents or solvent        mixtures that are substantially miscible with water, in order to        maintain the phase stability of the composition.

The organic solvent may be present in the composition of the presentinvention in an amount of 1 to 20 percent by weight, often 3 to 10percent by weight, based on the total weight of the composition.

-   -   The alkyl polyglucosides (d) which may be used in the present        invention are those corresponding to formula (III):

R₄O(R₅O)_(b)(Z₃)_(a)   (III)

wherein R₄ is a monovalent organic radical having from 6 to 30 carbonatoms; R₅ is a divalent alkylene radical having from 2 to 4 carbonatoms; Z₃ is a glucose residue having 5 or 6 carbon atoms; b is a numberranging from 0 to 12; and a is a number ranging from 1 to 6.Non-limiting examples of commercially available alkyl polyglucosidesinclude, for example, APG®, AGNIQUE®, or AGRIMUL® surfactants fromCognis Corporation, Cincinnati, Ohio; Atlox surfactants from Uniqema,New Castle, Del. 19720; or AG surfactants from AKZO NOBEL SurfaceChemistry, LLC, such as:

-   1. AGNIQUE PG 8105 Surfactant—an alkyl polyglucoside in which the    alkyl group contains 8 to 10 carbon atoms and having an average    degree of polymerization of 1.5.-   2. AGNIQUE PG 8166 Surfactant—an alkyl polyglucoside in which the    alkyl group contains 8 to 16 carbon atoms and having an average    degree of polymerization of 1.6.-   3. AGNIQUE PG 266 Surfactant—an alkyl polyglucoside in which the    alkyl group contains 12 to 16 carbon atoms and having an average    degree of polymerization of 1.6.-   4. AGNIQUE PG 9116 Surfactant—an alkyl polyglucoside in which the    alkyl group contains 9 to 11 carbon atoms and having an average    degree of polymerization of 1.6.-   5. AGNIQUE PG 264-U Surfactant—an alkyl polyglucoside in which the    alkyl group contains 12 to 16 carbon atoms and having an average    degree of polymerization of 1.4.-   6. AGNIQUE PG 8107 Surfactant—a C8-16 alkyl polyglucoside in which    the alkyl group contains 8 to 10 carbon atoms and having an average    degree of polymerization of 1.7.-   7. AGNIQUE PG 266 Surfactant—a C₁₂₋₁₆ alkyl polyglucoside in which    the alkyl group contains 12 to 16 carbon atoms and having an average    degree of polymerization of 1.6.-   8. AL 2575/AL 535 Surfactant—a C₈₋₁₁ alkyl polyglucoside in which    the alkyl group contains 8 to 11 carbon atoms and having a HLB    12-13.-   9. Akzo Nobel AG 6202, AG 6206, or AG 6210 surfactants which are 2    ethylhexyl branched C8; linear hexyl C6; and linear C8-C10 alkyl    polyglucosides respectively.    -   The alkyl polyglucoside may typically comprise a C₆-C₁₆ alkyl        polyglucoside. The alkyl polyglucosides most often used in the        composition of the present invention are those of formula III        wherein R₄ is a monovalent organic radical having from 8 to 10        carbon atoms; b is zero; and a is a number having a value from 1        to 3, typically 1.5 to 1.7, often 1.6.    -   The alkyl polyglucoside may be present in the composition of the        present invention in an amount of 1 to 15 percent by weight,        often 6 to 12 percent by weight, based on the total weight of        the composition.    -   While the liquid herbicidal compositions of the present        invention may be waterborne or solventborne, they are more often        waterborne (aqueous).    -   In the composition of the present invention, the weight ratio of        the water-soluble herbicidal ingredient (a) to the alkyl ether        sulfate (b) may range from 1:0.2 to 1:5.0, often 1:0.8 to 1:1.2.        In addition, the weight ratio of the water-soluble herbicidal        ingredient (a) to the organic solvent (c) may range from 1:0.02        to 1:1, often 1:0.1 to 1:0.3. While not intending to be bound by        theory, it has been observed that keeping the ratios of the        various ingredients within these ranges enhances the biological        activity of the herbicidal ingredient compared to when it is        used alone, without compromising the stability of the        composition. Moreover, the viscosity of the composition may be        maintained within a desired range.    -   Unlike concentrated herbicidal compositions of the prior art,        the composition of the present invention is both stable and        sprayable over a wide temperature range. The viscosity of the        composition is typically no more than 2000 cps, often no more        than 1500 cps, more often no more than 1000 cps, at temperatures        as low as 0° C. Viscosity may be measured using any technique        known to those skilled in the art, for example, using a        Brookfield Synchro-lectric Model LVT Viscometer. An apparent        viscosity is measured by first stirring the sample with a glass        rod for 10 seconds, placing the sample on the instrument,        turning the instrument on, and measuring the value after 3        revolutions of the measuring dial. Typically the measurement is        made using a #3 spindle rotating at 30 RPMs; however depending        upon the viscosity of the sample, different spindles and        differing rotational speeds can be utilized, as known by those        skilled in the art.    -   The composition of the present invention may optionally include        auxiliary agents commonly used in herbicide formulations and        known to those skilled in the art. Examples include wetting        agents, dispersants, emulsifiers, penetrants, preservatives,        antifreezes and evaporation inhibitors such as glycerol and        ethylene or propylene glycol, sorbitol, sodium lactate, fillers,        carriers, colorants including pigments and/or dyes, pH modifiers        (buffers, acids, and bases), salts such as calcium, magnesium,        ammonium, potassium, sodium, and/or iron chlorides, fertilizers        such as ammonium sulfate and ammonium nitrate, urea, and        defoamers.    -   Suitable defoamers include all customary defoamers including        silicone-based and those based upon perfluoroalkyl phosphinic        and phosphonic acids, in particular silicone-based defoamers,        such as silicone oils, for example.    -   Defoamers most commonly used are those from the group of linear        polydimethylsiloxanes having an average dynamic viscosity,        measured at 25° C., in the range from 1000 to 8000 mPas        (mPas=millipascal-second), usually 1200 to 6000 mPas, and        containing silica. Silica includes polysilicic acids,        meta-silicic acid, ortho-silicic acid, silica gel, silicic acid        gels, kieselguhr, precipitated SiO₂, and the like.    -   Defoamers from the group of linear polydimethylsiloxanes contain        as their chemical backbone a compound of the formula        HO—[Si(CH₃)₂—O—]_(n)—H, in which the end groups are modified, by        etherification for example, or are attached to the groups        —Si(CH₃)₃. Non-limiting examples of defoamers of this kind are        RHODORSIL® Antifoam 416 (Rhodia) and RHODORSIL® Antifoam 481        (Rhodia). Other suitable defoamers are RHODORSIL® 1824,        ANTIMUSSOL 4459-2 (Clariant), Defoamer V 4459 (Clariant), SE        Visk and AS EM SE 39 (Wacker). The silicone oils can also be        used in the form of emulsions.    -   The present invention will further be described by reference to        the following examples. The examples are merely illustrative of        the invention and are not intended to be limiting. Unless        otherwise indicated, all parts are by weight.

EXAMPLES

-   -   The following examples (1 to 9) illustrate the preparation of        various herbicidal compositions, demonstrating combinations of        co-solvents and alkyl polyglucosides and their combined effects        on stability. Examples 1, 3, and 7 are illustrative of the        invention while Examples 2, 4-6, 8, and 9 are comparative. The        ingredients were mixed together in a suitable vessel at room        temperature in the order listed and were observed for phase        separation at room temperature. Note that ingredients may be        mixed in other sequences, For example, the herbicide may be        added to the solvent package, provided the solution does not        phase separate.

1 2 3 4 5 6 7 8 9 Glufosinate 50% 44.00 44.00 44.00 44.00 44.00 44.0044.00 44.00 44.00 SLES (sodium lauryl 38.00 38.00 38.00 38.00 38.0038.00 38.00 38.00 38.00 ether sulfate) 70% BREAK THRU S200¹ 1.00 1.001.00 1.00 1.00 1.00 1.00 1.00 1.00 THFA 7.00 7.00 7.00(tetrahydrofurfuryl alcohol) Propylene glycol 7.00 7.00 7.00 monomethylether Dipropylene Glycol 7.00 7.00 7.00 Iso-propanol 3.00 3.00 3.00Iso-Butanol 3.00 3.00 3.00 1-Butanol 3.00 3.00 3.00 ¹Ethoxylatedtrisiloxane available from Degussa Corporation

AKZO 6206 Linear 5.00 5.00 5.00 Hexyl polyglycoside² AKZO 6202 2- 5.005.00 5.00 ethylhexyl polyglycoside³ AL 2575 C8-10 5.00 5.00 5.00 Alkylpolyglycoside⁴ Sodium Xylene 1.75 1.75 1.75 Sulfonate 40% aqueous SodiumToluene 1.75 1.75 1.75 Sulfonate 40% aqueous Ammonium Sulfate, 0.70 0.700.70 Granular FLUOWET PL80B⁵ 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.250.25 Deionized Water 1.05 1.05 1.05 RESULTS: Separation of sample No YesNo Yes Yes Yes No Yes Yes ²Linear hexyl polyglucoside available fromAkzo Nobel AG ³2 ethylhexyl branched polyglucoside available from AkzoNobel ⁴C₈₋₁₁ alkyl polyglucoside in which the alkyl group contains 8 to11 carbon atoms and has a HLB 12-13 ⁵Defoamer available from Clariant

Examples 10 to 12

-   -   Examples 10 to 12 illustrate the effects of dipropylene glycol        with various co-solvents. Example 10 is a composition of the        present invention while Examples 11 and 12 are comparative.

11 10% grams 12% grams % grams INGREDIENT: Glufosinate 50% 44.00 88.0044.00 88.00 44.00 88.00 SLES 70% 38.00 76.00 38.00 76.00 38.00 76.00BREAK THRU S200 1.00 2.00 1.00 2.00 1.00 2.00 Dipropylene Glycol 7.0014.00 7.00 14.00 7.00 14.00 Iso-propanol 3.00 6.00 Iso-butanol 3.00 6.001-butanol 3.00 6.00 AKZO 6206 Linear 5.00 10.00 Hexyl polyglycoside AKZO6202 2- 5.00 10.00 ethylhexl polyglycoside AL 2575 C8-C10 5.00 10.00Alkyl polyglycoside Sodium Xylene 1.75 3.50 Sulfonate 40% Sodium Toluene1.75 3.50 Sulfonate 40% PLANTAPON 1.75 3.50 CMGS¹ FLUOWET PL80B 0.250.50 0.25 0.50 0.25 0.50 TOTAL: 100.00 200.00 100.00 200.00 100.00200.00 RESULTS: Viscosity, cps-Initial 140 NT NT Room TemperatureAppearance-Initial no separation separation separation Room Temp NT—NotTested due to separation of samples in study. ¹Surfactant available fromCognis-Care Chemicals

Example 13 (Comparative)

-   -   Each composition in the following example contained, in parts by        weight:

Glufosinate 50% Concentrate 49 BREAK THRU 9903 Antifoam¹ 0.8 BREAK THRUS200 Silicone 0.6 Surfactant² Potassium Hydroxide 50% Solution 0.12^(1, 2)Available from Degussa Corporation

SLES Example Solution % AL 2575 % THFA % % Separation 13a 37.24 5.5 6.741.8 13b 35.62 4.5 9.36 17.8 13c 34 5.5 9.98 10.9 13d 34 4.5 10.98 12.9613e 34 3.5 11.98 23.6 13f 37.24 3.5 8.74 12.7 13g 36.43 5 8.05 10.7 13h35.08 3.5 10.9 21.8 13i 36.16 3.5 9.82 16.1 13j 35.08 5.5 8.9 7.4

-   -   While each of the mixtures in the above set exhibited some        degree of separation, the amount of separation was less as the        level of THFA solvent decreased and the level of APG surfactant        increased. Percent separation is a measurement of the height of        a separated phase compared to the total height of a sample.

Example 14

-   -   The following example illustrates the preparation of an        herbicidal composition in accordance with the present invention.        The ingredients were mixed together in the order listed:

INGREDIENT Percent by Weight Glufosinate 50% 48.600 AGNIQUE SLES 270¹34.544 AGNIQUE PG 8105² 9.850 THFA 5.500 BREAK THRU S200 0.600 BREAKTHRU AF 9903 0.800 Potassium Hydroxide 50% Solution 0.100 D&C Red 170.006 TOTAL 100.000

RESULTS Gms Glufosinate/liter 280.00 Lbs Glufosinate/Gal 2.335 Viscositycps—R.T. 216 Viscosity cps—40° F./4.4° C. 640 Viscosity cps—32° F./0° C.788 Viscosity cps—12° F./−10° C. 5400 ^(1, 2)Available from AKZO NOBELSurface Chemistry, LLC

-   -   Whereas particular embodiments of this invention have been        described above for purposes of illustration, it will be evident        to those skilled in the art that numerous variations of the        details of the present invention may be made without departing        from the invention as defined in the appended claims.

What is claimed is:
 1. A liquid herbicidal composition comprising: a. 20to 35 percent by weight of glufosinate or a salt thereof, based on thetotal weight of the composition; b. a lauryl ether sulfate or a saltthereof; c. an organic solvent; and d. a surfactant, wherein thecomposition is present in a continuous, single phase at a temperature aslow as −20 degrees C. and has a viscosity of no more than 2000 cps attemperatures as low as 0-degree C.
 2. The liquid herbicidal compositionof claim 1, wherein said glufosinate or salt thereof is present in anamount from 22 to 28 percent by weight, based on the total weight of thecomposition.
 3. The liquid herbicidal composition of claim 1, whereinthe organic solvent is present in an amount of 1 to 20 percent byweight, based on the total weight of the composition.
 4. The liquidherbicidal composition of claim 1, wherein said surfactant is present inan amount of 1 to 15 percent by weight, based on the total weight of thecomposition.
 5. The liquid herbicidal composition of claim 1, whereinsaid the weight ratio of said glufosinate or a salt thereof (a) to thelauryl ether sulfate (b) ranges from 1:0.2 to 1:5.0.
 6. The liquidherbicidal composition of claim 1, wherein said the weight ratio of saidglufosinate or a salt thereof(a) to the lauryl ether sulfate (b) rangesfrom 1:0.8 to 1:1.2.
 7. The liquid herbicidal composition of claim 1,wherein said (a) comprises a glufosinate salt selected from the groupconsisting of glufosinate-ammonium salt, glufosinate-potassium salt, andglufosinate-sodium salt.
 8. The liquid herbicidal composition of claim1, wherein said composition further comprises an agent selected from thegroup consisting of an auxiliary agent, a wetting agent, a dispersant,an emulsifier, a penetrant, a preservative, an antifreeze, and anevaporation inhibitor.
 9. A liquid herbicidal composition comprising: a.20 to 35 percent by weight of glufosinate or a salt thereof, based onthe total weight of the composition; b. a lauryl ether sulfate or a saltthereof; c. an organic solvent; and d. a surfactant, wherein thecomposition is present in a continuous, single phase at a temperature aslow as −20 degrees C. and has a viscosity of no more than 2000 cps attemperatures as low as 0-degree C.
 10. The liquid herbicidal compositionof claim 9, wherein said glufosinate or salt thereof is present in anamount from 22 to 28 percent by weight, based on the total weight of thecomposition.
 11. The liquid herbicidal composition of claim 9, whereinthe organic solvent is present in an amount of 1 to 20 percent byweight, based on the total weight of the composition.
 12. The liquidherbicidal composition of claim 11, wherein said surfactant is presentin an amount of 1 to 15 percent by weight, based on the total weight ofthe composition.
 13. The liquid herbicidal composition of claim 11,wherein said a) comprises a glufosinate salt selected from the groupconsisting of glufosinate-ammonium salt, glufosinate-potassium salt, andglufosinate-sodium salt.
 14. The liquid herbicidal composition of claim9, wherein said the weight ratio of said glufosinate or a salt thereof(a) to the lauryl ether sulfate (b) ranges from 1:0.2 to 1:5.0.
 15. Theliquid herbicidal composition of claim 9, wherein said the weight ratioof said glufosinate or a salt thereof (a) to the lauryl ether sulfate(b) ranges from 1:0.8 to 1:1.2.
 16. The liquid herbicidal composition ofclaim 12, wherein said the weight ratio of said glufosinate or a saltthereof (a) to the lauryl ether sulfate (b) ranges from 1:0.2 to 1:5.0.17. The liquid herbicidal composition of claim 12, wherein said theweight ratio of said glufosinate or a salt thereof(a) to the laurylether sulfate (b) ranges from 1:0.8 to 1:1.2.
 18. A liquid herbicidalcomposition comprising: a. 20 to 35 percent by weight of glufosinate ora salt thereof, based on the total weight of the composition; b. alauryl ether sulfate or a salt thereof; c. an organic solvent; and d. aC6-C16 alkyl polyglucoside, wherein the composition is present in acontinuous, single phase at a temperature as low as −20 degrees C. andhas a viscosity of no more than 2000 cps at temperatures as low as0-degree C.
 19. The liquid herbicidal composition of claim 18, whereinsaid glufosinate or salt thereof is present in an amount from 22 to 28percent by weight, based on the total weight of the composition.
 20. Theliquid herbicidal composition of claim 18, wherein the organic solventis present in an amount of 1 to 20 percent by weight, based on the totalweight of the composition.